Abstract: The effects of the structures of spectral sensitization dyes on photographic properties and on ionic conductivity of cubic AgX emulsion were investigated. The aggregations of dyes on AgX microcrystum and size distributions of J-aggregates by reflection spectrum and ACFEM were studied in this paper. The results show that all dyes used in this paper can form J-aggregate on cubic AgX emulsion, and the average size of J-aggregates of 5substituted thiacarbocyanine dyes is larger than that of 5-unsubsltltuted one. Thiacarbocyanine dyes which are 5substituted by electrondrawing groups or campact can increase ionic conductivity of emulsion. Thiacarbocyanine dyes are sensitizing dyes. The 6-nitro substituted indocarbocyanine dye is a typical desensitizing dye and their J-aggregates on cubic AgX emulsion are small but has no effect on ionic conductivity of emulsion.

Key words: sensitizing dye, silver halide microcystal, J-aggregate